SIG Sauer Forge Files
P320, M17/M18, P365, modular fire-control systems, grip modules, slides, magazines, optics, recoil systems, upgrades, maintenance, and the fitment details that matter before you start mixing SIG parts.
P320 | M17 / M18 | P365 | Compatibility | Reliability | Optics | Tuning
SIG's modular pistols make customization easy. They also make vague compatibility advice expensive.
P320 and P365 families can share design ideas without sharing parts. Even inside one family, grip length, slide length, magazine length, optic cut, recoil system, barrel configuration, fire-control components and model revision can change what fits. Verify the exact platform and interface before assuming modular means interchangeable.
Modular does not mean universal.
New to the SIG Library? Start Here.
The current SIG Forge library is heavily P320-focused. These three references give you the foundation before you start mixing modules, upper assemblies, magazines or optics.
SIG Sauer Reference Library — A–Z
Already know what you're looking for? Jump straight to the guide. Model names stay visible here because this hub will eventually contain multiple SIG platforms.
Browse by Platform
Start with the pistol family. The same SIG logo does not make P320 and P365 components interchangeable.
P320 Family +
FCU-driven modularity, grip modules, multiple slide lengths, magazine families, optics, recoil systems, controls and tuning.
Compatibility GuideWhat fits, what does not and what needs verified across the P320 family. Caliber Conversion & Parts Compatibility
9mm/.40/.357 FCU family, .45/10mm split, upper-system conversions, magazines and grip-module compatibility. Grip Module Guide
Standard, X-Series, TXG, AXG and aftermarket module fitment. Slide, Barrel & Recoil System Guide
Slide lengths, barrels, recoil assemblies and upper-system compatibility. Trigger & Fire-Control Guide
FCU architecture, trigger systems, aftermarket parts and function. Optics & Slide Cut Guide
Footprints, plates, screw fit, slide cuts and optic-generation differences. Magazine Compatibility & Troubleshooting
Magazine body length, basepads, grip fit, extensions and stoppage diagnosis. Reliability & Common Malfunctions
Feeding, extraction, ejection, lockback, return-to-battery and system-level diagnosis. Safety Systems, Drop Safety & Voluntary Upgrade
Internal safeties, 2017 drop-fire history, factory upgrade, manual safety, holsters and current evidence.
M17 / M18 +
P320/MHS variants with specific slide-length, manual-safety, loaded-chamber-indicator and optic-mounting questions.
M17 vs M18 — Compatibility, Parts & Setup4.7 vs 3.9-inch uppers, recoil assemblies, magazines, safety configuration, LCI and SIG-LOC vs commercial optic cuts. P320 Optics & Slide Cut Guide
Commercial PRO/DPP-style cuts, M17/M18 differences, plates and mounting compatibility. P320 Iron Sights & Co-Witness
M17/M18 rear sight plates, sight heights, optic deck height and backup-sight geometry.
P365-specific Forge Files are the next SIG family to build out. We are not creating empty article cards just to make this hub look full. When the P365 compatibility, grip, slide, magazine, optic and tuning references are finished, they will drop into this same architecture.
Browse by System
Know the system or problem, but not the exact article? Open the section that matches what you're working on.
Ammo & Function+
Compatibility & Fitment+
Issues & Solutions+
Maintenance & Wear+
Optics, Sights & Lights+
Recoil Systems & Compensators+
Safety & Function+
Triggers & Controls+
Grip length affects magazines and concealment. Slide length changes barrels and recoil assemblies. Optic cuts decide mounting. Compensators interact with ammunition and springs. Control changes affect holsters. FCU configuration can affect grip-module fit.
The modularity is the advantage. Understanding the interfaces is what makes it useful.
The IronKells Standard
SIG manuals, model specifications, compatibility information, service documentation and official technical material establish the factory baseline. They do not automatically answer every real-world aftermarket or tuning question.
Forge Files combine that baseline with reputable aftermarket documentation, technical testing, documented failure modes, experienced builders and IronKells hands-on observations when we actually have them. Known compatibility gets documented. Uncertain compatibility gets called uncertain instead of becoming a confident guess because two parts look alike.
P320 is the first fully developed SIG cluster. P365 comes next. Additional SIG platforms get added when there is enough researched material to build a real reference instead of an empty category.
Explore More of the Forge
Modular Doesn't Mean Guess.
Know the platform, verify the interfaces, and build the pistol around what actually fits and performs.
All Forge Files Glock Forge Files Contact IronKellsIRONKELLS ARMORY | SIG SAUER FORGE FILES
Receipts Over Rumors.
Know the platform. Verify the fitment. Build the configuration on purpose.